Many people were waiting for new properties to come on the market, Ms MacDonald said.
"It's sort of a double-edged sword because the people who are wanting to sell can't find anything to buy, so therefore they're a bit worried about putting their house on the market.
"But if they all think like that, then we get into a bit of a stalemate."
Well-priced, well-presented properties had been selling extremely well, Ms MacDonald said.
Meanwhile in Auckland, the market remained firmly in favour of sellers as the city chalked up another record high for asking prices, the report showed.
While national asking prices remained steady at $430,443, the Auckland region surged to $585,482 - the highest level in five years.
The asking price in Wellington and Canterbury fell in August, with Canterbury recording the lowest levels since January, down 4.8 per cent to $374,732.
Taranaki saw the biggest drop, down 6.7 per cent to $280,560.
However, property listings have started to flow back on to the market with the onset of the "spring splurge", with some regions experiencing significant lifts.
The Central North Island, Gisborne, Taranaki, Wairarapa and Otago reported year-on-year increases of more than 20 per cent. Wairarapa had the largest boost, with a 40.1 per cent increase in new listings.
Bay of Plenty reported the biggest drop-off, with 15.4 per cent fewer listings than at the same time last year.
Realestate.co.nz marketing manager Paul McKenzie said in addition to its high asking prices, Auckland had registered a record low for inventory - the amount of time a region's housing stock would take to sell - at just 18 weeks.
"The sellers' market that has persisted for much of this year has not abated, but buyer interest remains high, so the strong level of new listings should provide some healthy selection for spring," Mr McKenzie said.
The report came soon after this week's release of the QV Quarterly Property Report, measuring fluctuations in sales volumes and prices.
It found that the Auckland property market again was leading the way nationwide, while most provincial sale prices were stagnant or declining.
BY THE NUMBERS
$336,930 - the average asking price for a property in Hawke's Bay: 1.3 - percentage change from July
$430,443 - the average asking price for a property in New Zealand: 0.3 - percentage change from July
375 - new Hawke's Bay listings in August: -1.3 - percentage change from August 2011
10,365 - more property listings nationwide in August: 2.4 - percentage change from August 2011